Ignition system.



C. F. KETTERING.

IGNITION SYSTEM.

APPLICATION FILED Aus.l1. 1911.

1,223,180. I Patented Apr.17,1917.

II III I-W-ITIIEEIEES I UNITED STATES PATENT OFFICE.

CHARLES F. KETTERING, 0F DAYTON, OHIO, A-SSIGNOR TO THE DAYTON ENGINEERING I LABORATORIES 00., A CORPORATION OF OHIO.

IGNITION SYSTEM.

Patented Apr. 17, 1917.

Original application filed April 17, 1911, Serial No. 621,512. Divided and this application filed August 11,

To all whom it may concern:

Be it known that I, CHARLES F. KETTER- ING, a citizen of the United States, residing at Dayton, county of Montgomery, and

State of Ohio, have invented'certain new and useful Improvements in Ignition Systems, of which the following is a full, clear, and exact description.

This invention relates to an improvement in ignition systems and is particularly designed to prevent the waste of current in systems of this character.

The present invention is applicable to inventions of various types, but is especially adaptable to ignition systems of that character which have a continuous uni-directional flow of current from a limited source or supply.

In ignition systems wherein a limited source of continual electrical energy is employed for ignition purposes, it is very desira'ble that a minimum amount of electrical energy be consumed, consistent with the securing of the desiredresults in the-most advantageous manner. i

It is a frequent occurrence in ignition systems, where the main circuit is opened and closed intermittently by timing mechanism, to havecontact members which directly open and close the circuit in the above manner, brought into such position, when the I engine is brought to a stand-still, that the ignition circuit will remain closed, thus permitting a continuous flow of current to pass therethrough and a consequent partial or complete depletion of the source of electrical energy. p

One of the objects of the present invention, therefore, is to provide means con- 7 nected with an ignition circuit which will readily permit the normal flow of current therethrough, but which, upon an abnormal or continuous flow of current from the electrical source, will act to reduce and out down the amount of current flowing through the circuit, to substantially a negligible quan-.-

tity, and thus conserve the supply of current, even though the main circuit is closed, either through the action of the contact members or any other cause, for an extended length of time.

The present case is a divisional application of my co-pending application, filed April 17,1911, Serial No. 621,512.

e 1911. Serial No.643,547.

Further and incidental objects and advantages of the present invention will appear in the following description, reference being had to the accompanying drawings, wherein a preferred form of one embodiment of the present invention is illustrated.

Referring to the drawings, a diagrammatic View is shown, setting forth an ignition system-embodying the present invention.

The numeral 20, designates a limited source of continuous electrical energy which may be an accumulator or storage battery ofany approved type, one pole of which is connected with the wire 21, which leads to v the switch 22.

This switch may be of any suitable construction and is adapted to be manually operated to open and close the main circuit. The movable element of said switch is con- -nected at one end, with the wire 23, which in turn is secured to one terminal of the resistance coil 24:, the opposite terminal thereof, having a lead wire connection,-as at 25, with the terminal 26 of the induction coil, this winding 26, being connected by the wire 27 to the timing mechanism 28.

The secondary circuit comprises the secondary winding 29, and the distributor mechanism 30, having a plurality of spark circuits, 31, connected with the spark plugs 32 of the respective cylinders of the engine. The normal flow of current will obviously be from the battery 20, through wire 21,

switch 22,. wire '23, resistance coil 24, the function of which will be more fully described hereinafter, wire 25, primary winding 26, through the timing mechanism 28, back to the battery, via wire 34. I

It will thus be seen that a single spark impulse will be induced in the secondary.

winding 21, for each contact of the rotatable member 35 on the timing mechanism 28, with the fixed contact36, thereof.

As a generalrule, the moving member of the timing mechanism is actuated at substantially one-half engine speed, so that it will be appreciated that the closing of the main circuit by this timer mechanism, will normally be very short.

The resistance coil 24, which may be in the shape illustrated or in any other form is preferably constructed of iron wire, nickel or other metals having a normally low coeflicient of resistance, but thereslstance of which will be increased as the heat or tem perature thereof increases, that is, one of the properties of metals of this character being that they are normally good electrical conductors for current, up to a certain predetermined point, but beyond that polnt, the resistance thereof, materially increases as the temperature of the metals are raised by mechanism has been brought to a stand-still in such position that the circuit is closed thcrethrough, or from other causes, a con tinuous flow of 'current will be set up through the main circuit. If this flow of current is permitted to exist, asis generally the case, in ignition systems now in use, the supply of current contained in the battery or accumulator 20, would be materially reduced within a short time.

In the present invention, the interposition of the resistance coil 24: in series with the main circuit, will act as a good conductor for the normal flow of current through the said circuit, but if for any reason, an abnormal or continuous flow of current is created through the main circuit, the resistance coil 24, which is preferably composed of iron wire, will tend to heat up and with the rise in temperature thereof, 'a consequent increase in its resistance will result, this increase in the resistance progressing as the temperature of the wire rises, so that the abnormal fiow of current is gradually tapered ofl until the How of current through the circuit is practically reduced to a negligible quantity. 1

From the above, it will be obvious that while a normal flow of current through the circuit will in no wise be resisted by the 1ron wire, any material increase from the normal How of current will cause the iron wire to heat up and thus increase its resistance properties. i

It is to be understood that this invention has peculiar adaptability to an ignition sysaaaieo stop when the engine tops, in such a position that its contact arm;3 5 would remain resting upon the'conta'ct point 36. That is, there would be what might be termed a dwell of the current interrupter on this circuit closing position, which would mean a running down of the batteries.

There is, moreover, another advantage and result ofthis iron wire resistance, namely, that when the engine slows down in speed, the timer or current interrupter likewise slows down in speed, thus causing its contact arm 35 to remain longer in contact with the point 36 than would be the case when the engine is running at high speed. The result of this is that if the slow speed circuit is closed for a longer time through the iron wire, thus heating it up more than would be the case for high speeds, it naturally follows that in such event, the increase of resistance of the iron wire, diminishes the current in this circuit, andthus the induced spark is diminished for low speeds; (Ir, another way of expressing it, would be that with a constant source of current, the iron wire in this combination, results in the uti-' lizing of a variable amount of current for the variation in speed.

While I have described a preferred form of one embodiment of my invention, it should be understood that I do not desire to limit the invention by aid disclosure, but that I reserve the right to make such alterations and changes in said invention as may come within the scope and spirit of the present invention.

What I claim is as follows 1. In an ignition system, a source of electrical energy; a main circuit including a current interrupter; circuit connections between the current source and said circuit; and means for diminishing the flow of current in said main circuit without opening said circuit, when there is a dwell of said current interrupter ,in its circuit closing positime; 1

3. In an ignition system, a source of electrical energy; a main circuit including a current interrupter; circuit connections between the current source and the main circuit; and thermal resistance included in the main circuit, for diminishin the flow of current therein without opening said circuit, when there is a dwell of the current interrupter in its circuit closing position. 4:- In an ignition system, a source of electrical energy; a main circuit having connection with sa1d source; a current interrupter in the'main circuit; and an iron wire con an abnormal flow of current occurs therein.

5. In an ignition system, a source of electrical energy; a main circuit having connectionwith said source; a current interrupter in said main circuit; and an iron Wire connected in the main circuit, which iron wire becomes heated when there is an abnormal flow of current through the circuit, and by said heating thereby increases the resistance of said iron wire which increase of resistance is utilized to protect the circuit against the continued flow of the abnormal current.

6. In an ignition system, a source of current having circuit connections; a current interrupter included in said connections; and means dependent upon the frequency of operation of the interrupter for.automa'tically varying the resistance of said circuit connections in unison with the operation of said interrupter.

7. In an ignition-system, a source of electrical energy, an engine-actuated timing device, an electrical circuit connected with said source and interrupted by said engihe-actuated timing device, and thermally operated means for increasing the resistance of said circuit without interrupting the circuit When there is an abnormal flow of current through said circuit.

8. In an ignition system, a source of electrical energy; a main circuit having connection with said source; movable means for intermittently opening and closing said main circuit; and thermal means having ahigh temperature coefficient of resistance, which i is brought into eflect by the action of said movable means in closing saidcircuit and.

which operates by the heating increase of re-' sistance of said thermal means to limit the flow of current through the main circuit.

9. In an ignition system, a source of electrical energy; a main circuit including a current interrupter; circuit connections between the current source and the main cir' cuit; and means controlled by the current flow in said main circuit for changing the ,normal resistance conditions of said circuit and to restore said resistance conditions to normal.

In testimony whereof I aflix my signature in the presence of two subscribing witnesses.

CHARLES F. KETTERING. 

